1# Check for stdbool.h that conforms to C99.
2
3dnl Copyright (C) 2002-2006, 2009-2016 Free Software Foundation, Inc.
4dnl This file is free software; the Free Software Foundation
5dnl gives unlimited permission to copy and/or distribute it,
6dnl with or without modifications, as long as this notice is preserved.
7
8#serial 7
9
10# Prepare for substituting <stdbool.h> if it is not supported.
11
12AC_DEFUN([AM_STDBOOL_H],
13[
14  AC_REQUIRE([AC_CHECK_HEADER_STDBOOL])
15
16  # Define two additional variables used in the Makefile substitution.
17
18  if test "$ac_cv_header_stdbool_h" = yes; then
19    STDBOOL_H=''
20  else
21    STDBOOL_H='stdbool.h'
22  fi
23  AC_SUBST([STDBOOL_H])
24  AM_CONDITIONAL([GL_GENERATE_STDBOOL_H], [test -n "$STDBOOL_H"])
25
26  if test "$ac_cv_type__Bool" = yes; then
27    HAVE__BOOL=1
28  else
29    HAVE__BOOL=0
30  fi
31  AC_SUBST([HAVE__BOOL])
32])
33
34# AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future.
35AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H])
36
37# This version of the macro is needed in autoconf <= 2.68.
38
39AC_DEFUN([AC_CHECK_HEADER_STDBOOL],
40  [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
41     [ac_cv_header_stdbool_h],
42     [AC_COMPILE_IFELSE(
43        [AC_LANG_PROGRAM(
44           [[
45             #include <stdbool.h>
46
47             #ifdef __cplusplus
48              typedef bool Bool;
49             #else
50              typedef _Bool Bool;
51              #ifndef bool
52               "error: bool is not defined"
53              #endif
54              #ifndef false
55               "error: false is not defined"
56              #endif
57              #if false
58               "error: false is not 0"
59              #endif
60              #ifndef true
61               "error: true is not defined"
62              #endif
63              #if true != 1
64               "error: true is not 1"
65              #endif
66             #endif
67
68             #ifndef __bool_true_false_are_defined
69              "error: __bool_true_false_are_defined is not defined"
70             #endif
71
72             struct s { Bool s: 1; Bool t; bool u: 1; bool v; } s;
73
74             char a[true == 1 ? 1 : -1];
75             char b[false == 0 ? 1 : -1];
76             char c[__bool_true_false_are_defined == 1 ? 1 : -1];
77             char d[(bool) 0.5 == true ? 1 : -1];
78             /* See body of main program for 'e'.  */
79             char f[(Bool) 0.0 == false ? 1 : -1];
80             char g[true];
81             char h[sizeof (Bool)];
82             char i[sizeof s.t];
83             enum { j = false, k = true, l = false * true, m = true * 256 };
84             /* The following fails for
85                HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */
86             Bool n[m];
87             char o[sizeof n == m * sizeof n[0] ? 1 : -1];
88             char p[-1 - (Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];
89             /* Catch a bug in an HP-UX C compiler.  See
90                http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
91                http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
92              */
93             Bool q = true;
94             Bool *pq = &q;
95             bool *qq = &q;
96           ]],
97           [[
98             bool e = &s;
99             *pq |= q; *pq |= ! q;
100             *qq |= q; *qq |= ! q;
101             /* Refer to every declared value, to avoid compiler optimizations.  */
102             return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l
103                     + !m + !n + !o + !p + !q + !pq + !qq);
104           ]])],
105        [ac_cv_header_stdbool_h=yes],
106        [ac_cv_header_stdbool_h=no])])
107   AC_CHECK_TYPES([_Bool])
108])
109